1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel with an improved design for dummy ribs.
2. Description of the Related Art
A plasma display panel displays an image on a screen using light emitted when a fluorescent material or a special gas is excited. A plasma display panel is roughly classified into three groups: AC type, DC type, and hybrid type.
In a display area of a plasma display panel, barrier ribs are formed on a lower substrate in the display area before being attached to the upper substrate. Outside the display area, additional ribs, called dummy ribs may also be formed. Dummy ribs are formed to maintain distance between the upper and the lower substrate during the process of making the plasma display panel.
Often, the dummy ribs are formed in sets containing 3 or 4 ribs in parallel with each other. Japanese Patent Laid-Open Publication No. 2001-160360 discloses in FIG. 2 an AC type plasma display panel having a plurality of dummy ribs 11 outside a display region to reduce abnormal discharge. However, the design of dummy ribs 11 in FIG. 2 of JP 2001-160360 cannot withstand sandblasting. Sandblasting can cause one or more of the dummy ribs 11 to fail. When one or more dummy ribs 11 fail, the failed dummy ribs do not well serve to maintain proper distance between the upper and the lower substrates.